Chemical anchor bolt assemblies are used in supporting earth formations and are especially useful in providing roof supports in mining operations. Such roof supports are usually installed by drilling a hole upward in the roof of a mine. When the hole has been formed, chemical packets or containers of chemical anchor resin are placed in the hole formation.
A roof or anchor bolt is then inserted upward in the hole formation. The roof or anchor bolt is provided on the lower end with at least a plate and a nut such that the anchor bolt may be inserted upward in the hole formation until the plate and nut abut the roof of the mine.
The bolt assembly is then rotated such that the containers of the chemical anchor resin will be broken and mixed together. The resin is then allowed to harden in the hole formation until it rigidly secures the anchor bolt in the mine roof. The nut on the lower end of the anchor bolt is then torqued to a desired torque level.
One of the problems associated with installing such an anchor bolt in the roof of a mine is that the mine worker must usually use two separate tools. The first tool used must nonrotatably hold the bolt and nut such that it rotates the bolt in the hole to mix the chemical anchor resin.
When the resin has set, it is then usually necessary to change tools such that a second tool then grips and torques the nut on the lower end of the bolt assembly. For obvious reasons, it is not desirous for a machine operator to have to continually change tools on the machine for each step and, further, it is not desirous for the machine operator to have to keep track of a second tool working under conditions normally found in mining operations.
Recently, some advances have been made in the prior art as evidenced by U.S. Pat. No. 3,979,918, which has provided one solution to the above-mentioned problems.
U.S. Pat. No. 3,979,918 still requires special manufacture of nuts, threads and the like in order to accomplish the desired objective.
It is an object of the present invention to provide a method and tool for practicing the method that is simple, efficient and economical.
It is a further object of the present invention to provide a method and tool for practicing the method that will allow standard threaded rods and nuts to be used when installing chemical anchor bolt assemblies.
It is an object of the present invention to provide a single tool to be used by the operator when installing chemical anchor resin bolt assemblies in earth formations.